13-cis-Acitretin 13-cis-Etretin 2,4,6,8-Noneatetraenoic acid, 9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-, (Z,E,E,E)- 69427-46-9 Isoacitretin Ro 13-7652